Anisakis spp. larvae in different kinds of ready to eat products made of anchovies ( Engraulis encrasicolus ) sold in Italian supermarkets

Abstract

In this study the occurrence of visible anisakid larvae in semi-preserved anchovy products sold on the Italian market was investigated. Totally, 107 ready to eat products (33 salted-ripened, 49 in oil and 25 marinated) were sampled. Each sample was digested, then the digested material was observed under natural and UV light. Parasites were counted, collected and microscopically identified to genus level. A representative subset was molecularly identified using the cox2 gene. At least one visible Anisakis sp. larva was found in 54.2% of the total 107 products analysed and totally 1283 dead larvae were collected. Anisakis sp. larvae were found in all the 33 salted products and 1139 (88.8%) larvae were collected, with a range of 1-105 parasites per product. Larval density per gram was 0.13. Anisakis sp. larvae were found in 49.0% of the products in oil and 143 (11.1%) larvae were isolated, with a range of 0-28 and a density of 0.03. Only 1 larva was found in the 25 marinated products (4.0%, density 0.00). A highly significant difference between all the product categories in respect of number of larvae per product, frequency of products contaminated by at least one larva and larval density per gram was found. Within the subset of larvae molecularly analysed (n=122), 92 (75.4%) were identified as A. pegreffii and 30 (24.6%) as A. simplex. This study showed that semi-preserved anchovy products heavily contaminated with Anisakis spp. larvae reach the market. Beyond the negligible risk for anisakidosis, the presence of dead visible parasites may cause immediate rejection in consumers. In addition, the potential risk related to allergic reactions in sensitized individuals needs to be further assessed. In order to avoid commercialization of obviously contaminated products, fresh anchovies' batches intended for the production of such products should be accurately selected by the processing industry applying inspection methods.

Seafood products notifications in the EU Rapid Alert System for Food and Feed (RASFF) database: Data analysis during the period 2011–2015

“…(1.1%) and unspecified tapeworms (0.5%). Finally, one notification (0.5%) regarded swordfish fillets because of the presence of Pennella, which, although not dangerous for human health, can make products unfit for consumption (Guardone et al, 2018).…”

“…are available in the literature (Wharton, Hassall, & Aalders, 1999). Although in this case, the squids were frozen and thus larvae were inactivated, dead parasites are an increasing reason to consider products unfit for consumption (Bilska-Zając et al, 2016;Guardone et al, 2018).…”

Occupational disease due to Anisakis simplex in fish handlers

“…The most commonly affected commercial species are hake, whiting, cod, and mackerel, but the parasite has also been identified in a large variety of fish such as sole, john dory, sea bream, horse mackerel, herring, blue whiting, sardine, anchovy, haddock, monkfish, salmon, conger, and turbot, and in cephalopods, such as squid, octopus and cuttlefish [4][5][6][7]. We should also point out that studies confirm that the preva-lence in fish varies according to the fishing area and the size of the host, with larger fish having more infestations [7,8].…”

“…However, over the last few years there has been an increase in the number of cases reported in other countries including Italy [8,12] and Spain [6,13].…”

Viability of Anisakis spp. Larvae After Direct Exposure to Different Processing Media and Non-Thermal Processing in Anchovy Fillets

“…Most of the larvae are found on the visceral surface of the gastrointestinal tract and to a much lesser extent embedded in fillets [17,18]; however, Šimat et al showed that A. pegreffii larvae persist in anchovy fillets of live fish and that post-mortem migration during storage at both 0 and 4 • C is delayed by 3-5 days but still presumptive [22]. A recent study found significant numbers of dead Anisakis larvae in ready-to-eat products made of anchovies on the Italian market, which in addition to posing health risks for sensitized consumers, also represents extremely unpleasant experiences and can inflict economic losses [24].…”